表观弥散系数值在脑胶质瘤术前分级诊断中的应用价值

Application of ADC value in diagnosis of glioma grading before operation

目的:通过分析表观弥散系数(ADC)值在低级别胶质瘤及高级别胶质瘤的差别,探讨ADC值在胶质瘤分级诊断中的价值。方法:经手术病理证实的14例低级别胶质瘤(Ⅰ、Ⅱ级)和20例高级别胶质瘤(Ⅲ、Ⅳ级)患者术前常规MRI检查、增强扫描检查及磁共振弥散加权成像(DWI)扫描。在工作站构建ADC图,分别测量肿瘤实质部分、瘤周水肿区和囊变坏死区以及相应对侧正常脑白质的ADC值,分析各测量区的ADC值与胶质瘤病理分级的关系。结果:低级别胶质瘤肿瘤实质部分ADC值[(1.47±0.18)×10-3 mm2.s-1]明显高于高级别胶质瘤[(0.97±0.18)×10-3 mm2.s-1](P<0.01),相应对侧脑白质ADC值分别为(0.76±0.06)×10-3 mm2.s-1和(0.75±0.06)×10-3 mm2.s-1;低级别胶质瘤肿瘤周围水肿区ADC值[(1.61±0.19)×10-3 mm2.s-1]明显高于高级别胶质瘤[(1.26±0.14)×10-3 mm2.s-1](P<0.01),相应对侧脑白质ADC值分别为(0.74±0.04)×10-3 mm2.s-1和(0.77±0.06)×10-3 mm2.s-1;低级别胶质瘤囊变坏死区ADC值[(1.88±0.11)×10-3 mm2.s-1]明显高于高级别胶质瘤[(1.31±0.14)×10-3 mm2.s-1](P<0.01),相应对侧脑白质ADC值分别为(0.75±0.08)×10-3 mm2.s-1和(0.73±0.06)×10-3 mm2.s-1。脑胶质瘤肿瘤实质部分、瘤周水肿区、囊变坏死区的ADC值与肿瘤的恶性度呈负相关关系(r值分别为-0.821、-0.726和-0.919,P<0.01)。结论:低级别胶质瘤与高级别胶质瘤瘤体实质区、瘤周水肿区、瘤体囊变坏死区ADC值有明显差异,ADC值测量可作为脑胶质瘤术前分级诊断的指标之一。

Objective To study the value of apparent diffusion coefffcient（ADC） value in diagnosis of glioma before operation by analyzing the differences of ADC value between low grade glioma and high grade glioma.Methods The imagines of 14 cases of low grade gliomas（Ⅰ,Ⅱ grade） and 20 cases of high grade gliomas（Ⅲ,Ⅳ grade） with glioma histologically proved including conventional MRI,enhanced scanning and DWI were retrospectively analyzed.The ADC map in the station building was constructed and the ADC values of tumor substantial part,peritumoral edema,cystic necrotic area and the corresponding contralateral normal brain were measured.The relationship between the ADC value about the measurement area and the grade of glioma was analyzed.Results The ADC value of tumor substantial part of low grade glioma [（1.47±0.18）×10-3 mm2·s-1] was significantly higher than that of high grade glioma [（0.97±0.18）×10-3 mm2·s-1]（P0.01）,the ADC values of the corresponding contralateral brain white matter were（0.76±0.06）×10-3 mm2·s-1 and（0.75±0.06）×10-3 mm2·s-1;and the ADC value of tumor peritumoral edema of low grade glioma [（1.61±0.19）×10-3 mm2·s-1] was significantly higher than that of high grade glioma [（1.26±0.14）×10-3 mm2·s-1]（P0.01）,the ADC values of the corresponding contralateral brain white matter were（0.74±0.04）×10-3 mm2·s-1 and（0.77±0.06）×10-3 mm2·s-1.The ADC value of cystic necrotic area of low grade glioma [（1.88±0.11）×10-3 mm2·s-1] was higher than that of high grade glioma [（1.34±0.14）×10-3 mm2·s-1]（P0.01）,the ADC values of the corresponding contralateral brain white matter were（0.75±0.08）×10-3 mm2·s-1 and（0.73±0.06）×10-3 mm2·s-1.The ADC values of tumor substantial part,peritumoral edema,cystic necrotic area were inversely associeated with the degree of malignancy of the gliomas（the r values were-0.821,-0.726 and-0.919,respectively,P0.01）.Conclusion The ADC values of tumor substantial part,peritumoral edema,cystic necrotic area between low grade glioma and high grade glioma have significantly differences,the measurement of ADC value play an important role in diagnosis of glioma grading before operation.